Manufacture or production of chlorinated products of toluene and dyestuffs therefrom



.Patented fient. 1'12, T1822.)

TATES JULIUS SCHHI'DLIN, OF BERG-EN, NEAR FRANKFORT-QN-THE-MAIN, GEltMANY, AS

SIG-NOR T0 LEOPOLD CASSELLA &. CO. GESELLSCHAFT MIT BESCKTER HAZE TUNG, A CORPORATION OF GERMANY.

MANUFACTURE OB- PIt)D'UGTION OF CHLORINATED PRODUCTS 0F TOLUENE AND DYESTUFFS THEREFBOM.

(Ho Drawing. A

To all whom it may concern:

Be it known that I, JULIUS SGHMIDLIN, professor of chemistry, a citizen of the Swiss Republic, residing at Ber en (Borngasse 7 ,near Frankfort-on-theain, Germany, ave invented certain new Improvements in the Manufacture or Production of Chlorinated Products of Toluene and Dyestufis Therefrom, of which the following is a full description.

I have found that technically pure tetrachlorotoluene ma be obtained with a very satisfactor yiel by chlorinating in the presence 0 anhydrous iron chloride or iron, care being taken that the reaction is as \hompgenous as ossible. The tetrachlorotoluene thus pro uced may be either directly used for technical purposes, or suitably purified for instance by distillation. It can easily and with a very satisfactory yield be converted into tetrachlorobenzalchloride, if contrary to the indications given in Annalen 150 page 304 the chlorination in the side chain of the tetrachlorotoluene is not carried out at the boiling point (280 C.) of the tetrachlorotoluene, but at a considerably lower temperature, preferably between 100 and 130 C. The reaction then runs quite smoothly without the formation of byand split-products, andis considerably accelerated by the action of light and especially ultraviolet rays.

By heating the tetrachlorobenzalchloride with concentrated sulfuric acid the corresponding tetrachlorobenzaldehyde can be easily produced. This aldehyde has not yet been manufactured and is but vaguelyv referred to in literature, thus in the Annalen No. 150, page 303 and No. 152, page 245,

as follows :--Tetrachlorobenzaldehyde appears to form when heating tetrachlorobenzalchloride with water to 280 C.

I have further found that new and very valuable dyestufls of the triphenylmethane series result if this tetrachlorobenzaldehyde is condensed with o-oxycarboxylic acids and the leucocompounds thus produced arejthen oxidized. These new coloring matters sur-' Application filed March 12, 1915. Serial No. 13,949.

pass in intensity and fastness otherknown dyestufis of a similar character and are dis-- tinguished by their bright greenish blue shade.

The invention is illustrated by the followin examples xample I: 92 kilos dry toluene are charged with 1 kilo anhydrous chloride of iron. Dry chlorine is passed over the surface of the liquid whilst it is stirred, the temperature belng kept at 12 to 15 C. As soon as the thickening of the mass caused by the precipitation of crystallized substance indicates the transformation into trichlorotoluene, the stream of chlorine is interrupted and the mass is completely liquefied by heating to 45 to C. After cooling down to 35 C. chlorine is again introduced, the temperature being raised gradually from 35 to 50 C. so that the continuously stirred mass always remains a comparatively thin liquid. The introduc tion is interrupted as soon as the weight has reached approximately 220 kilos. A sam le diluted with the same volume of carbon isulfide should at the utmost show traces of precipitated pentachlorotoluene. When distilling, only a small quantity of a primary distillate is obtained, consisting of tetrachlorotoluene C HCLBH and small quantitles of trichlorotoluene. Then about 90% of the theoretical quantity of pure tetrachlorotoluene passes over between 266 and 276 C. After once crystallizing from ether, the substance shows a melting point of 92 0., as indicated in Annalen 150 page 289.

Example H: Tetrachlorotoluene is heated to 100 to 130 C. The liquor is subjected to the action of light, and chlorine is passed slowly into it. As soon as the absorbed quantity of chlorine corresponds to the formation of tetrachlorobenzalchloride,

C HChCI-lCI about 6 parts strong sulfuric acid, while' Example III 24 parts tetrachlorobenzah dehyde and 31 parts o-cresotinic acid are stirred with 150 ing graphical formula c ncrcm mci n, o iicofin may be directly oxidizedto the dyestufl, for

instance by adding to it a solution of 7.1

, parts dry sodium nitrite in a'sufiicient quanvtity of concentrated sulfuric acid and warming the mass to about 90 C. whilst stirring well until the formation of the dyestuif is completed; or the leucocompound, may purified by pouring on to ice, whereby it 1s precipitated, and then dissolved in dilute" soda solution. The impurities are removed by filtration and the leucocompound is preclpitated in a pure state by 'addin mineral Y into dyestufi it again dissolved in the adding necessary quantity of concentrated sulfuric acid and oxidized as indicated above by sodium nitrite, or in any other suitable manner.

By pouring this solution onto ice the acid claret red color, soluble in soda with a yellowish brown color and in caustic soda with an intense blue color.' By evaporating the soda solution, the sodium salt separates a the following graphical formula I arts strong sulfuric acidl until the aldehy c has disappeared. The leucocompound thus producedof the follow sulfuricihacid and-after cboling condense ,vvithjo v-cresotinic acid.- eAs oxidation agents ."nitric acid; nitro-compounds,; sulfuric acid or oleummay likewise be used.

reddish-brown crystalline powder having Gama[ ssapacoam]2 In an acid ibath wool is dyed fairly intense red or reddish brown shades, depending on 'the condition'of the wool; the afterchromed dyeing shows an intense greenish blue shade. F I In the" place "of o-cresotinic acid other o-oxy'carboxylic acids o rlmixture's thereof -m a be applied; the tetrachlorobenzaldeby e may-further be substituted by tetrachlorobenzalchloride which is v i reviously stlrred whlle heatlngto 29(29- C. with strong 'Havmgynow particularly described and ascertained the' nature; of my said invention acid being in a dry state a reddish' browncrystalline powder, being in the form of it.

.sodium salt soluble in water with a yellowish brown color, soluble in caustic soda with -a, deep blue color and in concentrated sulfuric acid with a claret red color, and d elng wool in an acid bath a red or reddlsh brown, depending on the condition of the wool, which'color, by afterchroming, turns into a beautiful reenis'h blue-shade distingulshed by its astness to washing, millng-anclpottmg, v

n witness whereof I'have hereunto signed myJ'iame this 12 day of February 1915, in the presence of two subscribing witnesses.

1 JULIUS SCHMIDLIN. Witnessesz' v J JEAN. GRUND,

' CARL GRUKD. 

